What type of fallacy occurs when an argument presents complex issues in an oversimplified manner?

The fallacy that occurs when an argument presents complex issues in an oversimplified manner is the straw-person fallacy. This type of fallacy involves misrepresenting or oversimplifying an opponent's argument to make it easier to attack or refute. By focusing on a distorted version of the original argument, the speaker diverts attention from the actual complexities and nuances of the issue, thus undermining genuine discourse.

In contrast, the other fallacies mentioned do not specifically address the oversimplification of complex issues. The red-herring fallacy diverts attention away from the main topic by introducing unrelated information, while the slippery slope fallacy suggests that a relatively small first step will inevitably lead to a chain of related events resulting in significant consequences, lacking a direct correlation. On the other hand, a non sequitur involves a conclusion that does not logically follow from the premises, but again, this does not specifically involve oversimplification of complex arguments.

Understanding the straw-person fallacy highlights the importance of accurately representing opposing viewpoints and engaging with the full complexity of issues during discussions and debates.